| 摘要 |
PURPOSE:To enhance sensitivity, raw preservability and the stability of an image by adding an electron donating leuco dye, a thioisocyanate compd. and an amino compd. to the thermal color forming layer formed on a support. CONSTITUTION:An electron donating leuco dye, for example, 2-anilino-3-methyl-6- N-methyl-N-n-propylaminofluorane, a thioisocyanate compd. and an amino compd. are added to a thermal color forming layer. As the thioisocyanate compd., for example, 2,6-dichloroethylthioisocyanate having two or more NCS groups is used. As the amino compd., a compd. represented by formula (wherein X is a direct bond, -CO-, -SO2-, -CONH-or -SO2NH- and R1-R3 are a hydrogen atom, an alkyl group, an aryl group, an alkoxy group, an aryloxy group, a halogen atom, a nitro group, cyano group, a hydroxy group, -CONHNH2-, -SO2 NHNH2- or a specific group) is used. |
